There have recently been provided electronic apparatuses in which camera modules are incorporated, for example, mobile telephones and PDAs (Personal Digital Assistants).
A camera module includes a lens holding member for holding an image pickup optical system, a barrel containing the lens holding member, a spring supporting the lens holding member in the barrel so that the lens holding member is movable along the optical axis of the image pickup optical system, an image pickup element for picking up a subject image guided by the image pickup optical system, and a driving unit for moving the lens holding member along the optical axis (see Japanese Unexamined Patent Application Publication No. 2007-108597).
In many cases, the lens holding member is molded by filling a molten synthetic resin from a gate of a mold into a cavity. In this case, to ensure the hardness required of the lens holding member, the synthetic resin contains fillers such as glass fibers.